How to Clean a Fish Tank: What to Scrub, What to Leave Alone
How to clean a fish tank with the fish still in it: the order of jobs, what to do weekly, and the gravel and filter steps that most guides get wrong.
Aquarium Filter Size and Type: How Much Flow Does Your Tank Need?
How big a filter does your tank need? The 4 to 6 times rule, why hobbyists argue about 10 times, and how sponge, hang-on-back and canister filters compare.
Sand vs Gravel in a Freshwater Aquarium: Which Substrate for Which Tank
Sand or gravel? What each means for bottom feeders, live plants and cleaning, how much to buy, and where the sources disagree about it.
How Long to Leave the Aquarium Light On: Start at 6 to 8 Hours
How long to leave an aquarium light on: start at 6 to 8 hours on a timer, never 24, and cut hours or brightness first when algae shows up.
How to Acclimate Fish to a New Tank: Float, Drip or Just Net Them?
How to acclimate new fish: float for temperature, net them out and never pour in the bag water. Where sources split on drip and plop-and-drop.
How to Set Up a Freshwater Aquarium: Step by Step, From Empty Tank to First Fish
How to set up a freshwater aquarium: where to put it, what you need, what to switch on and when, and how long to cycle before the first fish.
How Many Fish in a 10 or 20 Gallon Tank? Counts by Species, Not Inches
How many fish fit in a 10 or 20 gallon tank? Counts by species, with school sizes, floor-space checks and example stocklists built from sourced figures.
What Size Heater for Your Tank? A Wattage Chart for 5–40 Gallons
50, 100 or 150 watts for a 20 gallon? All three can be right. Match the heater to your room temperature, with a chart for 5, 10, 20, 29 and 40 gallons.
Setup & Gear
Tanks, filters, heaters and the gear that actually matters for a freshwater tank.